8 Replies Latest reply on Apr 22, 2017 4:31 PM by alexslv

Just curious - what will happen if I point two instances of SolarWinds to the same DB

alexslv Apr 19, 2017 10:15 AM

Anyone knows what will happen if SolarWinds app server fails and after recovering app server onto a different host and pointing to existing DB via Config Wizard, the original app server suddenly springs into live? ... In this case both of them potentially will try to talk to exact same database. How database will behave in such case? Are there any protection mechanisms to ensure data is not corrupted should that happen?

Same question for the NTA database server, as it does have connection back to SQL DB as well

Thanks a million for your help guys,

Alex

Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB

aLTeReGo Apr 19, 2017 1:04 PM (in response to alexslv)

Terrible, terrible things. The only protection mechanisms that exists are when the Configuration Wizard is run and it detects that it's not the owner of the database. If you proceed, that Orion instance will take ownership and the other instance will be rendered broken.
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- Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB
  
  alexslv Apr 20, 2017 6:02 AM (in response to aLTeReGo)
  
  Awesome, thanks Alterego, this just confirms my gut feeling that we should be super cautious here with our DR test runs
  
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- Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB
  
  alexslv Apr 21, 2017 11:02 AM (in response to aLTeReGo)
  
  aLTeReGo quick question if I may:
  
  If I will run the following script, which is part of app stack migration to new host, will it potentially stop original app host from messing up with the data should it come back to live?
  
  DECLARE @oldHostname nvarchar(max)
  SET @oldHostname = 'OLDHOST'
  DECLARE @newHostname nvarchar(max)
  SET @newHostname = 'NEWHOST'
  UPDATE Engines SET ServerName = @newHostname WHERE ServerName = @oldHostname
  UPDATE OrionServers SET HostName = @newHostname WHERE HostName = @oldHostname
  UPDATE WebSettings SET SettingValue = @newHostname WHERE SettingName = 'JobSchedulerHost'
  UPDATE Websites SET ServerName = @newHostname WHERE ServerName = @oldHostname
  
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  - Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB
    
    aLTeReGo Apr 21, 2017 11:26 AM (in response to alexslv)
    
    I see where you're going, but I don’t think that would be sufficient. After running that script, the new server will have replaced the old one (mostly – there are other references such as in the Subscriptions table). If the old server rises from the dead, it will see that it has no entry in the Engines table and it will create one. If it is an APE, this will have little or no effect. But if it is (was) a main server, it will register in the Engines table as a second main server and then things will be messed up.
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    - Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB
      
      alexslv Apr 22, 2017 4:31 PM (in response to aLTeReGo)
      
      Thanks alterego, this really clarifies a lot of things. Appreciate your help Thanks a million
      
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Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB

d09h Apr 20, 2017 9:02 AM (in response to alexslv)
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Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB

rschroeder Apr 20, 2017 9:26 AM (in response to alexslv)
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Re: Just curious - what will happen if I point two instances of SolarWinds to the same DB

d09h Apr 21, 2017 1:49 PM (in response to alexslv)
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